Thanks, @gulshankumar for being helpful
I tried your recommendations but it didn’t work. All of my static resources are now showing 404 Not Found error (they are running over HTTPS protocol). I also tried disabling the SSL feature but still, the same problem persists.
I also tried by deleting the entire Zone and recreating it. But didn’t work.
The Chrome’s Console tab is showing this error: https://i.imgur.com/1TofjGH.png
They give LetsEncrypt SSL for one Zone Alias but after I created an Alias they didn’t issue any LetsEnrypt SSL for that Alias. The Alias was run over my Single Domain Comodo certificate. I also configured CNAME settings as per their saying.
Their support is also very bad. I sent a complaint last night but still, I am not getting any replies from them. Also, they have not any live chat support.
UPDATE: All resources are accessible via the plain HTTP protocol. What could I do to make it accesible via HTTPS protocol.